Dual conduit air-conditioning system

ABSTRACT

An air-conditioning system including first and second central station apparatus for supplying conditioned primary and secondary air, respectively, to a plurality of enclosed areas in a building. A constant volume of secondary air is supplied to a preselected area. The temperature of the area is sensed and the first central station apparatus is operated to provide a constant volume of primary air to each of the enclosed areas at a temperature related to the temperature sensed in the preselected enclosed area. Secondary air is supplied to each of the other areas simultaneously with the supply of secondary air to the preselected area, the volume thereof being regulated to provide a desired temperature condition in each of the areas.

United States Patent inventor Appl. No.

Filed Patented Assignee William S. Ostrander Chamblee, Ga. 25,124

Apr. 2, 1970 Nov. 30, 1971 Carrier Corporation Syracuse, N .Y.

DUAL CONDUIT AIR-CONDITIONING SYSTEM 4 Claims, 1 Drawing Fig.

[5 6] References Cited UNITED STATES PATENTS 3,441,080 4/1969 Church Primary Examiner-Carroll B. Dority, .lr, AnorneysHarry G. Martin, .ir. and .1. Raymond Curtin ABSTRACT: An air-conditioning system including first and second central station apparatus for supplying conditioned primary and secondary air, respectively, to a plurality of em closed areas in a building. A constant volume of secondary air Q l 49 l I PATENTEnunv 30 I97! 3, 623 543 INVENTOR. WILUAM S. OSTRANDER ATTORNEY 1 DUAL CONDUIT AIR-CONDITIONING SYSTEM ture containing a plurality of enclosed areas. A dual conduit system is designed to supply two airstreams apparatus varies the psychometric properties of the air supplied thereto, which may consist of a mixture the trade name ofFreon-IZ," is controllably expanded into the dehumidifier coils to obtain the desired supply air temperature.

The air conditioning system disclosed set the cooling load in each of the enclosed areas supplied by people, lights and machinery, etc.

When the primary air system is sized for solar as well as transmission load compensation, it is necessary to adjust the object of this invention is an air conditioning system of al conduit type, whereby the temperature of the primary air is readily adjusted to compensate for ambient temperature and/or solar load variations without the problems heretofore encountered.

The e du SUMMARY OF THE INVENTION This invention relates to a dual conduit system having a first The airstream will includes a second constant temperature and which may BRIEF DESCRIPTION OF THE DRAWINGS The FIGURE of the drawing is a schematic diagram showing the dual conduit type air conditioning system of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing,

generally by the numeral 12, and a conduit system I4, 15, for conducting primary and secondary air, respectively, to each of the areas or room l8 of the building served by the air conditioning system. Equipment section 12 maybe in the basement or on the roof of the building.

supply air, arranged in within a suitable housing 32.

Housings 28 and 32 are connected by duct 33 with return air and exhaust fan 34. The inlet of fan 34 is connected with with the areas or enclosed rooms 18 being served inlet air control vanes 35 are provided to vary the flow of air through fan 34. Adjustable vanes 36 are provided to vary the flow of return air to the primary air conditioning apparatus. Exhaust dampers 37 connect duct 33 with the outdoors. Dampers 37 control the volume of return air discharged to the atmosphere.

Housing 28 connects with primary air fan 38. Conduit means 14 conveys primary air from fan 38 to the areas or rooms 18 being conditioned. Runout conduits 42 lead to the individual rooms 18. Runout conduits 42 each have at least one outlet terminal 44 for discharge of supply air to the room.

Housing 32 is connected with the outlet of return air fan 34. Preferably, adjustable vanes 45 are provided to vary the flow of supply air to the secondary air conditioning apparatus. Adjustable vanes 46 are provided to regulate the flow of outdoor air to the secondary air conditioning apparatus.

Conduit means conveys air from fan 47 to the area or rooms being conditioned. Runout conduits 48 have one or more individual rooms 18. Runout conduits 48 have one or more outlet terminals 49.

The temperature of the primary and secondary air being conditioned by the primary and secondary conditioning apparatus is regulated by the operation of refrigeration machinery 50. Refrigeration machinery 50 represents any one of the three basic refrigeration cycles. The refrigeration machinery supplies a relatively cold medium to the dehumidifying coils and 31 to regulate the temperature of the primary and secondary air. In the preferred embodiment, the relatively cold medium is diclorodifluoromethane, marketed under the trade name of F reon-l2, or a similar refrigerant which may be directly expanded through valves 51 and 52 into the respective dehumidifying coils. The cold medium is supplied from the refrigeration machinery by conduit 53 and is returned thereto by conduit 54 and pump 55.

Each of the enclosed areas has a thermostat 56, which senses the temperature of the particular room. One of the thermostats 56' generates a signal related to the sensed temperature. The thermostat 56' is of a conventional type well known to those skilled in the art. The signal generated thereby is supplied to damper controllers 61 and 62. In the preferred embodiment, the control signal from thermostat 56 is pneumatic. However, it is within the scope of the invention for such signal to be electric. The signal operated to position dampers 59 and 60 to regulate the flow of air over coils 25 and 26 or about same to bypass the coils so the primary air temperature may be varied in a range from 55 F. to 125 F. The manner in which same is accomplished shall be more fully explained hereinafter.

OPERATION As noted hereinbefore, a dual conduit system is designed to permit temperature regulation by the occupants of each of the enclosed areas 18 to obtain desired temperature conditions in each of said areas. The secondary air supplied to each of the areas basically compensates for cooling loads supplied by people, lights, machinery, etc. The primary air supplied to each of the enclosed areas is designed to compensate for transmission losses or gains caused by variations in the temperature of the outside or ambient air. In addition, the primary air is designed to compensate for changes in the cooling load caused by variations in the solar effect on each of the areas.

As noted above, difficulties have been encountered when solar compensating devices have been utilized with systems of the type described above. To obviate such difficulties, the present invention discharges a constant volume of secondary air through terminal 49' located in what is hereinafter referred to as a control room or area, that is, a room which has been preselected as having a relatively constant people, light and machinery cooling load. A reception area is typical of such a control area. The constant volume of secondary air substantially compensates for the above-mentioned cooling load in the area. The room thermostat senses the temperature of the room; any increase or decrease of temperature above the design operating point is indicative of the transmission or solar load factors operating thereon.

A control signal related to the sensed temperature is generated and is supplied to the damper controllers 61 and 62. Controllers 61 and 62 position dampers 59 and 60 to regulate the flow of primary air over coils 25 and 26. When cool air is required, the control signal operates to position damper 59 so the flow of primary air is routed over coil 25 and additionally operates to position damper 60 so the flow of primary air bypasses coil 26. As less cooling is required, damper 59 is positioned to bypass a portion of the primary air about coil 25.

When the thermostat senses heating is required, due to a negative transmission load, that is, heat is flowing from the enclosure to the ambient air, the control signal supplied to damper controller 62 is operable to position damper 60 to direct the primary air over heating coil 26 and is additionally operable to position damper 59 via controller 61 to completely bypass dehumidifying coil 25.

Primary air, at a temperature controlled by the quantity of air being routed over or bypassed about the primary air coils 25 and 26, is passed from the primary air supply fan 38 through conduit means 14 to each of the areas or rooms being conditioned. As noted hereinabove, the primary air supplied to each of the rooms is at a constant volume. The primary air is thus applied at a temperature operable to compensate for transmission and/or solar factors.

Simultaneously with the supply of the constant volume of secondary air to the control area, secondary air is also supplied to each of the other areas. The room terminals in such areas are regulated to provide a varying volume of the secondary air to each of the areas. Volume regulation may be obtained by having the room thermostat sense the temperature and provide a control signal to position the damper means regulating the supply of secondary air. The damper control signal may be pneumatic or electric. Thus, by regulation of the supply of secondary air to each area, a predetermined temperature condition may be obtained for each area irrespective of the temperature in any other area.

It is readily apparent that the air conditioning system disclosed herein operates to provide temperature regulation for each of the areas in an enclosure without having the problems heretofore encountered when solar compensation has been provided. The system readily compensates for solar load deviations by operating in the manner described above.

While I have described and illustrated a preferred embodiment of my invention, it should not be limited thereto but may be otherwise embodied within the scope of the following claims.

I claim:

1. A method of air conditioning a building containing a plurality of enclosed areas, having first and second central station conditioning apparatus for supplying respectively, conditioned primary and secondary air to each of the enclosed areas comprising the steps of:

A. supplying a constant volume of secondary air to a preselected enclosed area;

sensing the temperature of the air in the preselected enclosed area;

C. generating a signal, the magnitude thereof being related to the temperature of the air in the enclosed area;

D. supplying a constant volume of primary air to each of the enclosed areas, the temperature thereof being related to said signal; and

E. supplying secondary air to each of the other enclosed areas simultaneously with the supply of secondary air to said preselected enclosed area, the volume thereof being controlled to obtain the desired temperature for said area.

2. An air conditioning system for conditioning the air in a plurality of enclosed areas in a building including first and second central station conditioning apparatus for supplying primary and secondary air to each of the enclosed areas comprising:

6 A. means for supplying a constant volume of secondary air air supplied to each of said other areas, said last-mento a preselected enclosed area; tioned means operating to obtain the desired temperature B. means for sensing the temperature of the air in said for said area.

preselected enclosed area including means for generating 3, Th h d i accordance i h l i 1 h i h a control signal related thereto; 5

supply of primary air is operable to regulate the temperature means operable to recewe the Comm] 3 to regulate of the air in each of the enclosures to compensate for transthe operation of Said first central station P mission losses and solar load factors present in each of the areas. 22 1 222332 5 253 to Sald control slgnal to each of the l 0 4. The air conditioning system in accordance with claim 2 D means for Suplying conditioned secondary air to each of wherein the primary air supplied to each of the areas compenother areas in the enclosure simultaneously with the sates for transmission losses and solar load factors present in supply of secondary air to said preselected area, said the area means including means to vary the volume of secondary UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 23,5 6 Dated November 30, 1971 Inventor(s) WILLIAM S OSTRANDER It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 26, "coil" should read --cold-- Column 1, line 60, after "exposure" insert the-- Column 1, line 6 4, before "cooling" insert --a-- Column 2, line 1 after "the" delete "airstream will" and insert --system- Column 3, lines 17, 18, after "48" it reads "have one or more" should read --lead to the 5-... v

Column 3, line 38, before "thermostat" delete "The" Column 3, line M, "operated should read --opera.tes-- Signed and sealed this 11 th day of July 1972.

(SEAL) Attost:

EDI'JARD MJ LETCHI'IM, JR. HOTLLHT GOTTSCHALK Attesting Officer Commissioner of Patents FORM 1169) USCOMM-DC mane-p09 9 U 5. GOVERNMINY PIINYNG OFFICE "G! O-$G-3ll 

1. A method of air conditioning a building containing a plurality of enclosed areas, having first and second central station conditioning apparatus for supplying respectively, conditioned primary and secondary air to each of the enclosed areas comprising the steps of: A. supplying a constant volume of secondary air to a preselected enclosed area; B. sensing the temperature of the air in the preselected enclosed area; C. generating a signal, the magnitude thereof being related to the temperature of the air in the enclosed area; D. supplying a constant volume of primary air to each of the enclosed areas, the temperature thereof being related to said signal; and E. supplying secondary air to each of the other enclosed areas simultaneously with the supply of secondary air to said preselected enclosed area, the volume thereof being controlled to obtain the desired temperature for said area.
 2. An air conditioning system for conditioning the air in a plurality of enclosed areas in a building including first and second central station conditioning apparatus for supplying primary and secondary air to each of the enclosed areas comprising: A. means for supplying a constant volume of secondary air to a preselected enclosed area; B. means for sensing the temperature of the air in said preselected enclosed area including means for generating a control signal related thereto; C. means operable to receive the control signal to regulate the operation of said first central station conditioning apparatus to supply a constant volume of primary air at a temperature related to said control signal to each of the enclosed areas; and D. means for supplying conditioned secondary air to each of the other areas in the enclosure simultaneously with the supply of secondary air to said preselected area, said means including means to vary the volume of secondary air supplied to each of said other areas, said last-mentioned means operating to obtain the desired temperature for said area.
 3. The method in accordance with claim 1 wherein the supply of primary air is operable to regulate the temperature of the air in each of the enclosures to compensate for transmission losses and solar load factors present in each of the areas.
 4. The air conditioning system in accordance with claim 2 wherein the primary air supplied to each of the areas compensates for transmission losses and solar load factors present in the area. 